Critical severity · published Apr 20, 2026
CVE-2026-6643
A stack-based buffer overflow vulnerability in the VPN Clients on the ADM
9.9
CVSS
0.5%
EPSS
No
On KEV
Description
A stack-based buffer overflow vulnerability was found in the VPN Clients on the ADM. The issue stems from the use of unbounded sscanf() and passing user-controlled data directly to printf(). Due to the lack of PIE and Stack Canary protections, an authenticated remote attacker can exploit these to execute arbitrary code as the web server user.
Affected products and versions include: from ADM 4.1.0 through ADM 4.3.3.RR42 as well as from ADM 5.0.0 through ADM 5.1.2.REO1.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AD
ADM · ASUSTOR Inc.
4.1.0 through 4.3.3.RR42; 5.0.0 through 5.1.2.REO1 · source: vendor
DM
Data Master · Asustor
4.1.0.rhu2 before 4.3.3.RR42; 5.0.0.ra82 before 5.1.2.reo1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-6643
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-6643
Vendor Advisory
https://www.asustor.com/security/security_advisory_detail?id=54
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